A Dirty Job: Compartment syndrome in a confined-space rescue

Tuesday, November 18, 2008

On the evening of Sept. 24, 2008, a 9-1-1 call was received reporting " man trapped in a tank" at the Brooklyn (N.Y.) Greenpoint Wastewater Treatment Plant. Dispatch immediately sent a patrol officer, as well as BLS and ALS units, to the site. While they were responding, the call was also assigned to Haz Tac #1 and a rescue medic unit. Arriving Brooklyn Fire units confirmed the incident and requested a full confined-space matrix response. With the arrival of the Haz Tac officer minutes later, the incident was managed as a mass casualty situation.

Crews learned that a maintenance worker, wearing waders and a harness, had entered a three-story reinforced concrete waste digester via a 24" manway located in the basement of the facility. He became trapped by a shifting mountain of semi-solid digested waste sludge at the flange of the manway.

The 43-year-old male patient was found with a head-outward orientation, slightly left lateral recumbent, with his left leg trapped below the knee at a 90_ angle to his body. The sheer weight of the thousands of gallons of sludge and the resulting suction of the digested waste made self-rescue impossible.

Assessment & ExtricationFire Rescue Companies 4 and 2 used shovels and other hand tools, feverishly trying to extricate the victim. Due to the flowing waste, machinery hazards, respiratory protection concerns (line EMS personnel don_t have SCBAs) and several asbestos abatement areas, the Haz Tac officer directed these crews to return to street level and report to the Division 3 patrol captain.

Haz Mat Company #1 was performing air monitoring and found no immediate issues in the environment with regard to high- or low-oxygen content, methane flammability, hydrogen sulfide poisoning or other potential contaminates. Infectious microbial contamination had to be assumed and factored into the incident action plan and post-incident medical follow-up for response personnel.

The patient was covered in waste. He was conscious, alert and in only a moderate amount of pain and distress. He was placed on an SCBA to keep his face and airway free of sludge. Several MSA/SCOTT FAST PACKS were utilized to supply him with air until a specialized air delivery cart was brought in to supply air to the SCBA face piece via hose. However, the flow of sludge caused several regulators to clog, requiring frequent face piece and regulator changes.

The operation progressed slowly because the only other access into the tank was from the roof via a similar manway. The size of this manway precluded the use of a barrel cofferdam to assist in protecting and freeing the patient, a tactic often used in trench rescue situations.„

Fire hose streams were deployed from above to jet the sludge from around the patient_s leg. As the amount of water increased the viscosity of the sludge, the torrent of effluence became worse. The flow constituted a slip hazard to the members operating in the basement, as it quickly rose to knee level. A Decontamination Task Force was requested and assembled, consisting of fire and EMS Haz Tac resources.

Medical ComplicationsThe torrent of cold water and the inevitable heat sink of the metal flange and concrete walls rapidly induced hypothermia in the patient. The EMS haz tac officer consulted with the Haz Mat battalion chief and requested that either a hot air blower or hot water heater be brought in to warm the patient or a garden hose of running water to wrap around the patient_s trunk as a temporizing measure to stave off worsening hypothermia. Due to the patient_s severe contamination, IV vascular access was not initiated.

A 4:1 hauling system was used to apply force to attempt to pull the patient free of the sludge, with no success. Because the tension was likely reducing arterial circulation via the femoral artery, and venous return from the femoral vein, a suspension-like iatrogenic trauma worsening the compartment pressure had to be suspected. By this point, it was two hours into extrication, and the patient was exhibiting serious fatigue, was shivering uncontrollably and in worsening pain.

OutcomeMore forceful means of extrication by the 4:1 hauling system were not needed. Thirty minutes later, the patient was freed and placed into a Stokes litter where he could be fully and rapidly examined by the on-scene EMS medical director and rescue medics. The patient was then taken upstairs to a decontamination station and later transferred to an ALS unit that had been given direction to administer glucose, sodium bicarbonate, IV fluids and pain management medications while en route to the closest trauma center.

Once the rescue operation was secured, the technical decontamination operation began, utilizing a decontamination shower truck for some 40 fire department members. EMS equipment, rescue equipment and PPE needed technical decontamination as well. The operation was secured at 0200 hrs, four-and-a-half hours after the 9-1-1 call, with no injuries to EMS or fire personnel.

The patient remained hospitalized for several weeks following the incident to recover from neurological sequelae of the compartment syndrome of his lower leg, notable weakness and "dropped foot," which is consistent with some of the reported sequelae of deep posterior compartment syndrome. Compartment syndrome is seen infrequently in the deep and posterior compartments of the leg, whereas the anterior compartment is cited most often in the literature as a consequence of trauma or extreme over-exertion.„

Lessons LearnedThere were many lessons learned from, and reinforced by, this incident. Most glaringly, was that EMS responses to technical rescues are fraught with danger to responders and patients. Fatalities in confined-space rescue often involve would-be rescuers and untrained first responders. By recognizing the situation and harnessing the innate impulse to rush in and help, EMS personnel can stay safe and ready to receive the patient. Technical rescue operations should have exclusion zones similar to hazmat setup to keep untrained personnel out of harm_s way.

Two of the axioms of MCI management are prompt notification and the proper staging of resources. The success or failure of an MCI response is made in the first critical minutes when, if proper notifications and staging areas aren_t accomplished, it can take hours to correctƒif correction is possible at all.

Finally, this incident highlights the need for responders to be familiar with their department_s policy on reporting biological exposures. The hazards associated with operating at incidents involving sewage contamination are many; protect yourself and your family by reporting these incidents and following up with your physician or employee health services department.JEMS